OFFSET
1,1
FORMULA
a(n) = n + floor(sqrt(n) + sqrt(n+1)).
a(n) = n + floor(sqrt(4*n + 1)). [Mircea Merca, Feb 05 2012]
MAPLE
MATHEMATICA
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Clark Kimberling, Jan 19 2011
STATUS
approved